The present invention generally relates to a spoke for a bicycle wheel. More particularly, the invention relates to a spoke which has a flattened portion and a geometric discontinuity that orients the flattened portion of the spoke in a desired position of use. The invention most particularly relates to a bicycle wheel comprising a plurality of such spokes.
As known, spokes for a bicycle wheel comprise an elongated body, generally made from metal like steel or aluminum or alloys thereof, provided with a first end for attachment to the hub and a second end for attachment to the rim on which the tire is mounted. Typically, the end for attachment to the hub is shaped so as to define a head intended to be housed in suitable seat and/or opening formed in the hub; the end for attachment to the rim, on the other hand, typically has a threaded zone to allow the attachment to the rim and the adjustment of the tension of the spoke through the application of a suitable nut or nipple.
In order to enhance the aesthetics appearance and the sports performance of the wheels, as well as the safety and comfort of the cyclist, flattened spokes have been proposed, i.e. spokes having a flattened body portion between the two ends. The flattened spokes, if correctly orientated when mounted onto the hub and rim, give the wheel an original aesthetic appearance and allow the visibility and aerodynamics of the wheel itself to be increased, at the same time reducing its noisiness during travel.
Some known spokes comprise a substantially cylindrical wire-shaped element having a frusto-conical head for attachment to the hub, a threaded end for attachment to the rim and a cylindrical intermediate portion having a flattened zone at the crossing zones of the spokes when mounted on the wheel. The head for attachment to the hub is intended to be housed in a seat formed on the side surface of the hub; such a seat is open at the front surface of the hub.
The present invention relates to a bicycle spoke comprising an elongated body extending along a longitudinal axis X-X. The elongated spoke body has a first end that includes a portion for attachment to a bicycle wheel hub, a second end that includes a portion for attachment to a bicycle wheel rim and an intermediate portion, between said first and second ends, that includes a portion flattened in a direction Z perpendicular to said longitudinal axis X-X. At least one of the end portions includes a surface discontinuity that mates with a hub or rim discontinuity to preserve said flattened portion of said spoke in a desired orientation during assembly and use.
Further characteristics and advantages of the present invention shall become clearer from the following detailed descriptions of preferred embodiments which are made with reference to the attached drawings. In such drawings:
Throughout the present description and the subsequent claims, the expression: flattened portion means a portion that has been worked along the transversal direction Z so that the cross section of such a flattened portion is of a size in one dimension that is substantially smaller than the other dimension. The opposite faces of the flattened portion do not have to be perfectly flat and parallel; i.e. the faces can have an elliptical or ovate progression with a wide bending radius.
Throughout the descriptions and claims, the expression, “surface of revolution,” indicates a surface oriented about and rotatable about an axis when the surface is in abutment with a corresponding coupling surface of another body. For example, a surface of revolution can be cylindrical, spherical, parabolic, toroidal, concave, convex, etc.
Providing a geometric or surface discontinuity in the surface of revolution defines a univocal coupling position between a spoke and a seat in the other body, thus preventing the relative rotation of the spoke with respect to the hub or rim. In particular, the rotation of the spoke about its longitudinal axis is prevented by the abutment action of the aforementioned discontinuity against the abutment surface. Therefore, the correct orientation of the flattened portion of the spoke is ensured in the assembly step of the wheel and it is ensured that such correct orientation is maintained during travel, even following knocks or vibrations and/or under conditions of improper tension that involve a loss of abutment tension.
The spoke of the present invention is suitable for being associated with conventional hubs in which the seats are formed on the side surface and are open at the front and with conventional hubs in which the seats are formed on the side surface and are closed at the front. In some cases, it may be necessary to modify the seat to make the abutment surface for the discontinuity; however, this is a minor and inexpensive modification that does not alter the original functionality of the hub.
A particularly advantageous aspect of the spoke of the present invention is the possibility of obtaining the benefits of the aforementioned spoke without the need for added steps in the conventional spoke production process. For example, it is possible to modify the mould or die for the manufacturing of the spoke head shape to obtain the desired discontinuity. Any additional cost of manufacturing the spoke of the present invention should therefore be relatively low.
For the sake of simplicity, throughout the present description reference shall often be made to the coupling between spoke and hub. Those skilled in the art will understand that there is an analogous application to the coupling between spoke and rim.
In the attached figures, a spoke for bicycle wheels in accordance with the present invention is indicated generally as 10. The spoke 10 comprises an elongated body 20, preferably made from metal like steel or aluminum or alloys thereof (for example aluminum alloy), extending along a longitudinal axis X-X. Such a type of spoke is intended to be used in a bicycle wheel, see
The portion for attachment to the hub 100 comprises, in particular, an end 32 having a head 31 for attachment to the hub 100. The head 31 comprises a substantially frusto-conical surface of revolution 310 that extends from the base surface 33 up to the body end portion 32. Here, the end 32 adjacent to the head 31 is defined by a substantially cylindrical surface of revolution 320 that joins to the flattened portion 60.
In accordance with the present invention, the surface of revolution 310 of the head 31 includes a geometric or surface discontinuity that prevents the rotation of the spoke 10 about its longitudinal axis X-X both during travel and during the assembly and/or tensioning steps of the spoke itself, as shall be described more fully hereafter.
In the embodiment of the spoke of the present invention illustrated in
As illustrated in
As illustrated in
The seats 110 comprise a first housing portion 120 for the head 31 of the spoke 10 and a second housing portion 130 for passage of the spoke body end 32 adjacent to the head 31 (see
Still with reference to the embodiment of the hub 100 illustrated in
In the embodiment of the hub 100 illustrated in
In this case, the spoke 10 is positioned in such a way that both the surface of revolution 310 of the head 31 and the projection 70 partially project in a trough or groove 170 formed circumferentially on the inner side surface 151 of the hub 100 at the seats 110. The rotation of the spoke 10 about its longitudinal axis X-X is thus prevented by the abutment action of the projection 70 against the inner side surface 151 of the hub at the throat or groove 170. It will be appreciated that the hub of
Further alternative embodiments of the spoke of the present invention are illustrated in FIGS. 5 to 11. One skilled in the art shall, however, understand that it is possible to imagine and manufacture different embodiments to those illustrated and/or described here still applying the same inventive concept, which is that of providing a discontinuity or irregularity in the surface of revolution to interrupt the symmetry of revolution of such a surface were it to have a continuous uninterrupted geometry. The man skilled in the art shall also be able to evaluate, according to the specific embodiment of the spoke considered, whether and what possible modifications it is necessary to make to the hub so as to make it suitable for coupling with the spoke under consideration.
The embodiment illustrated in
In an alternative embodiment illustrated in
The embodiment illustrated in
The embodiment illustrated in
In the embodiment illustrated in
In the embodiment illustrated in
In the embodiment of
The embodiment illustrated in
In use, the head 31, when fully inserted into the bushing 80, comes into abutment against the inner surface 85. The thusly arranged spoke 10 is then associated with the hub 100 by screwing the male threads 82 into a corresponding female threads in the respective housing seat 110.
In
Referring now to
Preferably, the discontinuities according to the present invention is presented as a curved surface. Advantageously, that a curved surface mates with or couples in abutment with a correspondingly curved surface for retaining the head in the respective seat both during the assembly step and following displacements caused during travel by knocks or vibrations.
Number | Date | Country | Kind |
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05425328.1 | May 2005 | EP | regional |